Microfoams are known in the art. The term “microfoam” is generally understood to mean a mass of small bubbles. Foam substances characterized as “microfoam” generally have smaller bubbles than those of a regular foam, which gives the microfoam a liquid-like consistency.
Microfoams are desirable in the beverage industry. Most of these beverage microfoams are usually produced by “frothing” the liquid with steam.
In the specific field of preparing coffee beverages, creamier and shinier microfoams, made of milk, cream, chocolate, or any other ingredient, are very much in demand. The connoisseur appreciates, and often demands, the smooth, velvety taste of a microfoam-like substance, which sits afloat their beverage and is an enjoyable aspect of their coffee-drinking experience. Such microfoams can be made manually by a barista, who is generally an expert in the foaming art, and who can create homogeneously creamy and tasty foams that mix with the coffee, thereby making a latte, for example. This microfoam can also be manipulated to make “latte art” (i.e. designs out of the microfoam). The consistency of the microfoam to be produced this way can often vary. For example, for a classic “dry” cappuccino, the foam should be light and floats on top of the more dense espresso. The latte, however, requires a heavier “wetter” foam, that can mix with the coffee.
It is known that foam is created when stem is introduced into a solution, such as milk. Milk can be foamed because of its low surface tension. Proteins in the milk, such as casein and whey, help in the creation of foam because they attract and hold air from the steam, the air acting as an emulsifier. The air-to-milk ratio is a parameter which may determine foam density and viscosity and which may affect the ability to create several types of specialty coffee beverages. It is also known that the size of the bubbles in the foam affect its texture, sometimes referred to in the field as its “feel” or “creaminess”. The smaller that the bubbles can be made in the foam, the more creaminess the foam will have for the consumer of the beverage.
Although a microfoam can be made in a variety of ways, the highest quality microfoams are currently achieved manually, whereby a barista or other operator uses a steam wand in conjunction with a professional espresso machine. However, this technique of producing a microfoam is barista-dependent, and the quality of the microfoam can change with the barista. Another disadvantage of such a system is that the creation of a steamed microfoam involves designing a complex and expensive water system, which must comply with numerous consumer safety standards.
It is also desired to use microfoams in colder speciality beverages as well, the most common of these being iced cappuccino and iced lattes. Typically, the microfoam created for these types of beverages is made from cold milk at around 4° C. Steam wands are not suitable for creating cold microfoams. Furthermore, it is often time-consuming and not commercially feasible to make fresh cold microfoams on demand, especially in the busy environment of a modern-day coffee shop.
An additional disadvantage of known techniques for making microfoams is that they work relatively well with microfoams made from homogenous liquids such as milk and cream, for example, but do not lend themselves to easily making microfoams from different, non-homogenous liquids such as the liquid obtained by insufficiently pre-mixing water with one or more condensed solutes, such as condensed milk.
There remains a need for devices and/or methods for producing a foam having the consistency generally associated with a microfoam, which by virtue of their components, steps, and design, satisfy some of the above-mentioned needs and are thus an improvement over other related devices and/or methods known in the art.